Measurement of the Step/Skirt Performance Index

PMT

Page 1 Copyright © 1995 – 2007 Physical Measurement Technologies, Inc.

Measurement of the Step/Skirt Performance Index Overview The step/skirt performance index is calculated from the measurement of two quantities and is defined only for the inclined section of the escalator. The first quantity is the loaded gap(Lg). This is the distance between the edge of the step and skirt, while the step is ‘pushed away’ from the skirt using a force of approximately 110 N (25 lbs.). The second quantity measured is the coefficient of sliding friction (µ) between the skirt panel and a standard polycarbonate test sample (PMT supplied). The Index is defined as: (a) Step/Skirt Performance Index = ey/(ey + 1) Where: y = -3.77 + 2.37(µ) + 0.37 (Lg) e = 2.7183 (Lg in mm) Specifically, the measurements are made on each side of two steps, separated by at least 8 steps. One step should be representative of the typical step. Additionally, the operator should attempt to identify the worst case step and make the measurements on this step as well. IMD-1 Operations Making accurate Step/Skirt Performance Index measurements is a multi-step process. A total of four distinct measurements are made per escalator. It is therefore very important that a consistent process be followed to ensure reliability and repeatability of the measurements. Following a consistent process will also make it significantly faster and greatly reduce mistakes. Step 1: Attach a new friction shoe (PMT part number IFS-1) to the IMD-1. Each shoe should be bent along the scribe line so that 2 ramps are formed. The ramps are intended to allow the shoe to pass over small misalignments in the skirt panels. Unlock and rotate the IMD-1 sensor housing so that the ramps are oriented in the direction of the incline.

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Page 2 Copyright © 1995 – 2007 Physical Measurement Technologies, Inc.

Step 2: Attach the IMD-1 to the selected step (With the Escalator Switched Off). It is suggested that the IMD-1 be placed in the center of the step (front to back). When attaching the IMD-1 to the escalator, be careful not to over tighten the tread lock knobs. Additionally, place the IMD-1 so that the friction face is about 25mm (1 inch) from the step edge. This will allow the operator to set the zero distance position more easily. Step 3: Attach the IMD-1 cable to the Sensor Input connector if using the MMC-1 data collector, or to the accelerometer analog input if using the EVA-625 as the IMD-1 data collector. Note: Do Not Connect to the I/O connector on the EVA-625. The I/O connector is used for serial communications. Step 4: Measure Index (EVA-625, MMC-1) Selecting Measure Index, leads to a sub-menu that allows the operator to either record index data (from the IMD-1), or display the index analysis in real time. Because the analysis of the step/skirt performance index data is so computationally demanding, the EVA-625/MMC-1 real time display should be considered as an estimate. The analysis performed on the PC provides the most accurate measure of the index and would normally be used for final analysis and documentation. The real time mode offers the ability for field personnel to quickly identify the locations on the escalator where either excessive loaded gap or friction are problematic.

Record Event Real Time Mode

Remove Accelerometer & Connect IMD-1 to Accelerometer Input

Attach IMD-1 to the Escalator Step, DO NOT OVERTIGHTEN

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Page 3 Copyright © 1995 – 2007 Physical Measurement Technologies, Inc.

Record Event The recording of the step/skirt performance index measurements is a multi-step process that involves making a series of 4 measurements. It is important to first identify the steps to be measured and it is suggested that they be marked. Although the measurements can be made in any order, for the purposes of discussion we’ll start with Step 1 Right.

Step 1 Right Step 1 Left Step 2 Right Step 2 Left

After attaching the IMD-1 to the EVA/MMC, select Step 1 Right. The Set ID # message will be displayed. This allows the user to save up to six digits as an identifier to be stored with each recording. This is very important. There will be one set of 4 IMD-1 recordings for each escalator. The ID# associates all recordings with a specific ID number such that: 1. Each Recording with the Same ID Number Will Have the Same Base File Name 2. Earlier Recordings Still in the EVA Memory Will Be Overwritten with Later Recordings If They

Have the Same ID#. This has an advantage such that if a mistake was made during a recording the latter recording will be saved.

3. The ID Number Must Be changed for each escalator After setting the ID # the message:

Go to Step 1 Left Set Distance to 0 ENT/START TO BEGIN

Set Distance to 0 This is an important part of the procedure. This establishes the gap distance as zero (friction face is aligned with the step edge pointer) prior to any measurements. To do so, push the friction shoe and follower fully back to the stop position against the IMD-1 housing. Then press the ENT key on the EVA-625 or MMC-1.

Setting Zero After setting the zero position the message: ALIGN POINTER

ADJUST SPRING PRESS ENT OR START SWITCH TO CONTINUE

will be displayed.

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Page 4 Copyright © 1995 – 2007 Physical Measurement Technologies, Inc.

Align Pointer PMT provides a Step Edge Alignment Tool with each IMD-1 Step/Skirt Performance Index measurement device to assist in the alignment of the step edge pointer with the step edge. This will minimize errors in the loaded gap measurement. After setting distance = 0: 1. Insert the Step Edge alignment tool between the step and the skirt with ridge up and handle placed directly

against the IMD-1 chassis.

2. Pull alignment tool tight against step edge. This provides a vertical face against which to push the pointer against. Push IMD-1 body (and pointer) gently against the alignment tool.

3. Lock IMD-1 into position (both sides) and remove step end alignment tool.

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Page 5 Copyright © 1995 – 2007 Physical Measurement Technologies, Inc.

Adjust Spring (Load) This adjustment is used to apply the 110N (25 lb.) Normal Force (friction face against the escalator skirt). To apply the full force, rotate the adjusting knob clockwise until bottomed. Do not tighten, simply rotate until the locknut touches the IMD housing. Rotate Clockwise to Add Force After pressing the ENT key the message WAITING FOR TRIGGER will be displayed. At this point the ENT key or EVA start switch can be pressed to begin the recording. Then the escalator should be started. After completing the recording of the incline, escape from recording and then stop the escalator.

Important: The Step/Skirt Performance Index is defined only for the inclined section of the escalator. Attach the IMD-1 at the beginning of the incline, and run the escalator through to the end of the incline. It is very important to not allow the IMD-1 to impact the comb plate or deflector or brushes that may be present.

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Page 6 Copyright © 1995 – 2007 Physical Measurement Technologies, Inc.

After finishing any specific recording, the Normal Force Must be released before releasing the IMD-1 from the escalator step. This is done by rotating the Normal Force Adjust knob counter clockwise to its fully extended position. Simply rotate to the stop position, do not tighten. Always turn off the EVA-625 or MMC-1 from the Main Menu. Data files can be corrupted by switching the MMC-1 off from any other than the Main Menu. The procedure should be followed for each side of the two selected steps. Real Time Mode Real Time mode allows the operator to quickly evaluate the step/skirt performance. The same set-up procedure is followed as with the recording. However, the data is not stored, the loaded gap, coefficient of friction and estimated index are displayed on the EVA-625/MMC-1 LCD. The measurements are updated each 0.5 seconds, displaying the maximum for the preceding time interval. Additionally, the Index threshold at which the LED will switch-on can be selected between .15, .25, or .4.

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Page 7 Copyright © 1995 – 2007 Physical Measurement Technologies, Inc.

EVA Analysis Tools Software (EVA-625, MMC-1)

Data Analysis Downloading of the data from the EVA-625/MMC-1 is accomplished as shown in their respective manuals. Select File Note that there are four files for each escalator. When displaying the list of escalator files, the Type Recording should be set to Escalator. Each file for one set of recordings will have the same base file name with slightly different file extensions. It is only necessary to select any one of the 4 files to analyze.

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Page 8 Copyright © 1995 – 2007 Physical Measurement Technologies, Inc.

Analysis After selecting the file of interest, select Analysis from the menu bar. This will display the data from each of the four recordings (assuming a full set of recordings were made for one escalator).

The graphical display presents the three time histories for each recording. The display is divided into four columns. The first column includes the loaded gap, coefficient of friction, and calculated step/skirt performance index (from top to bottom respectively) for Step 1, Right. The second column is Step 1, Left. The third column is Step 2, Right, and the fourth column is Step 2, Left. The measurement that is reported is the maximum index value.

Max: 0.257

Max: .142

Max: .256

Max: 0.244

Max: .215

Max: .253

Max: 0.233

Max: .182

Max: .216

Max: 0.259

Max: .196

Max: .261

Step 1, Right Step 1, Left Step 2, Right Step 2, Left

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0 5 10 15 20 25 30 35 40 45 50 55 60

1 2 3

Index Test Escalator 0001 File: EY097EXT.EU2 10:45:23 09/07/00

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